Cyclopropane carboxylic acid esters

ABSTRACT

CYCLOPROPANE CARBOXYLIC ACID ESTERS OF PHENOXYBUTYNYL ALCOHOLS. THE PHENYL RING MAY INCLUDE A CHLORO OR LOWER ALKYL SUBSTITUENT. THE ESTERS ARE USEFUL AS INSECTICIDES.

United States Patent Osbond et al. {451 Sept. 25, 1973 CYCLOPROPANE CARBOXYLIC ACID [56] References Cited S FOREIGN PATENTS 0 APPLICATIONS Inventors: J hn M r yn s fi 2,000,636 7 1970 Germany .7 260/468 Primary Examiner-Lorraine A. Weinberger Assistant ExaminerRobert Gerstl Asslgnec: Roche Attorney-Samuel L. Welt, Jon S. Saxc, Bernard S.

Nmlcy- Leon, William H. Epstein, Georgo M. Gould and R0- [22] Filed: Apr. 27, 1971 nald A. Schapira [2i] Appl. No.: 139,296

I [57] ABSTRACT Foreign Application Priority Data 30} June 8. 1970 Great Britain ..2758l/70 fgfgggg z zgg gg g fi $211133; {52] Cl 260/468 25 lower alkyl substituent. The esters are useful as insecti- 511 Im. Cl. C07c 69/74 [58] Field of Se archm- 260/468 H 10 Claims, No Drawings l CYCLOPROPANE cmnoxvuc ACID ESTERS SUMMARY OF THE INVENTION In accordance with this invention, it has been found that esters of the formula:-

wherein W is chlorine or bromine; with an alcohol of the formula:

wherein X is as above. The compounds of formula I are also prepared by reacting a salt having the formula:

wherein Z is an alkali metal, silver or triloweralkylammonium; with a halide of the formula:

wherein X is as above and hal is a halogen.

III

The compounds of formula I are further prepared by reacting a compound of the formula:

H30 c113 HaC C c-o HBC/ (fi-o-oH- C c-CHc1 1 with a compound of the formula;

X WQ I wherein X is as above and is an alkali metal.

DETAILED DESCRIPTION OF THEINVENTION The term lower alkyl, as used throughout this application, comprehends both straight-chain and branched-chain saturated alkyl hydrocarbon groups containing from 1 to 6 carbon atoms such as methyl, ethyl, butyl, and isopropyl, with methyl being preferred.

The term halogen or halo, as used herein, when not expressly stated otherwise, includes all four halogens, i.e., bromine, chlorine, fluorine and iodine, with chlorine being preferred.

The term alkali metal, as used herein, comprehends the alkali metals of the first group of the periodic chart, such as sodium, potassium and lithium, with sodium being preferred.

The term triloweralkylammonium", as used herein, means the cation of the reaction salt of a carboxylic acid and a triloweralkylamine. By triloweralkylamine, asjust used, is meant that each of the three alkyl groups attached to the amine nitrogen is a lower alkyl, as defined above. The term triloweralkylammonium includes cations such as triethylammonium and tri-isopropylammonium.

As mentioned above, the esters provided by this invention are useful as insecticides. They are active against a variety of insects (particularly against Musca domestica). Furthermore, these esters have been found to have a very low mammalian toxicity. For example, 4-phenoxy-2 -butynyl-2,2 ,3 ,3-tetram ethylcyclopropane carboxylic has an LD of greater than 1,600 mg/kg per os in mice, and 4-(4-chlorophenoxy)-2-butynyl= 2,2,3,3-tetramethyl-cyclopropane carboxylate has an LD of 1600 mg/kg per os in mice. These esters have shown an activity against Musca domestica on the order of that of pyrethrin extract and DDT, and they have. also shown an activity against bean aphids, colorado beetle, redspider mites and codlin moth.

The esters of the invention can be used in the form of insecticidal compositions which contain them in association with a compatible carrier material. Such insecticidal compositions can be made up in liquid form (e.g. as a sprayable solution or suspension) or in solid form (e.g. as a dust or granulate), either of which includes therewith a compatible carrier. The term compatible carrier" is used in this specification to mean a substrate which is inert towards the esters of formula I, which can be used to dissolve, disperse or diffuse the esters without impairing their effectiveness and which does not permanently damage the environment to which it is applied (e.g. crops, soil, equipment, etc.). For example, liquid compositions can be extended with water and dusts and granulates can be extended with inert solid carriers. Where a solid carrier is used in the preparation of insecticidal compositions, the carrier may be talc, finely powdered clay, silica or any similar carrier which does not bring about decomposition of the esters. Where the esters of formula I are formulated into liquid compositions, such compositions can include emulsifiers and/or acceptable organic solvents. If desired, the compositions can also contain conventional additives such as wetting agents or the like, as well as other insecticidally-active compounds and/or synergists.

An effective amount of an insecticidal composition can be applied to an insect-infested area using any conventionally accepted method such as spraying, dusting, etc. Desirably, solid compositions and liquid compositions contain from about 0.5% to 25 percent (preferably from about 1 to percent) by weight of an ester of formula I. The choice of concentration of an ester of formula I and the rate of application to the insectinfested area will, of course, depend on several factors; for example, the type and maturity of insects present, the type of composition applied and the mode of application.

It will be appreciated that the insecticidal compositions can take the form of concentrates (e.g. wettable powders or emulsion concentrates) suitable for storage and containing, for example, from about 10 to 80 percent by weight of an ester of formula I. The concentrate can be diluted with the same or a different carrier to a concentration suitable for application to an insectinfested area. Emulsion concentrates can be prepared, for example, by dissolving an ester of formula I in an acceptable organic solvent and adding an emulsifier which is soluble in the organic solvent.

Any organic solvent can be used including hydrocarbons (e.g., toluene and xylene), chlorinated hydrocarbons (e.g., perchloroethylene), ketones, esters, etc. or mixtures thereof. Preferably, the solvent should be water immiscible, and the especially preferred solvents are aromatic hydrocarbons and ketones.

Surfactants are useful as emulsifiers, and when used, they suitably constitute from about 5 to percent by weight of an emulsion concentrate. Preferably, the surfactants should be non-ionic.

In accordance with this invention, among the preferred compounds of formula I are the esters having the formula:

wherein Y is hydrogen or lower alkyl substituted in the ortho or para positions. Among the particularly preferred compounds of formula I are included the following compounds of formula la:

4-(2methyl-phcnoxy-2-butynyl-2,2,3,fi-tetramethylcyclopropane carboxylate;

4-(4-methyl-phenoxy)-2-butynyl 2,2,3,3-tctramcthyl-cyclopropane carboxylate; and

4-phenoxy-2-butynyl-2,2,3,3-tetramethylcyclopropane carboxylate.

Also among the preferred compounds of formula I, in accordance with this invention, are the esters having the formula:

Among the particularly preferred compounds of formula I are included the following compounds of formula Ib:

4-(2-chloro-phenoxy)-2-butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate and 4-(4-chloro-phenoxy)-2-butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate.

Among the particularly preferred compound of formula I, quite particularly preferred is 4-phenoxy-2- butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate.

One method for preparing the compounds of formula I involves reacting an acid chloride or bromide of formula II with an alcohol of formula III.

The acid chloride and acid bromide starting materials of formula II are known substances. They can be conveniently prepared by first reacting tetramethylethylene with methyl or ethyl diazoacetic acid ester in the presence of copper powder or anhydrous copper sulfate, using excess tetramethyl-ethylene or toluene as the solvent, and subsequently chlorinating or brominating the resulting 2,2,3,3-tetramethyl-cyclopropane carboxylic acid with thionyl chloride, phosphorus tribromide, or the like. In this reaction, anhydrous copper sulfate is the preferred reagent and toluene is the preferred solvent. The acid chlorides are the preferred starting materials of formula III.

The alcohol starting materials of formula III can be prepared, for example, by reacting a halo-butynol of the formula:

wherein hal is as above, preferably chlorine; with an alkali metal salt of a phenol of formula VII, hereinbefore, preferably a sodium salt. In carrying out this reaction, temperature and pressure are not critical, and the reaction can be carried out at room temperature (about 25C.). Generally, it is preferred to carry out this reaction at an elevated temperature. A temperature of between 50C. and C. is especially preferred. The reaction can be carried out in any conventional inert organic solvent, preferably a lower alkanol, methanol and ethanol being especially preferred lower alkanols.

The reaction of an acid halide starting material of formula II with an alcohol starting material of formula III is conveniently carried out in the presence of an acid-binding agent. In this reaction, any conventional acid-binding agent can be used. Among the preferred acid-binding agents are alkali metal carbonates, such as sodium carbonate, alkali metal bicarbonates, such as sodium bicarbonate, and tertiary organic amines, such as triethyl amine, pyridine and the like. An especially preferred acid-binding agent is pyridine. This reaction is conveniently carried out in the presence of an inert organic solvent. Any conventional inert organic solvent can be used. Among the preferred solvents, are included hydrocarbons, such as benzene, toluene or xylene, ethers such as diethyl ether or dioxane, and halogenated hydrocarbons, such as methylene chloride, chloroform or the like. In carrying out this reaction, temperature and pressure are not critical, and this reaction can be carried out at room temperature. Generally, it is preferred to carry out this reaction at a temperature within the approximate range of from 0C. to C., with about 20C. being especially preferred. The reaction is also preferably carried out under the atmosphere of an inert gas. Any conventional inert gas may suitably be used, with nitrogen or argon being particularly preferred.

Another method of preparing the compounds of formula I involves reacting the alkali metal salt, the silver salt or the triloweralkylamine salt of a cyclopropane carboxylic acid of formula IV with a halide of formula V.

The alkali metal and triloweralkylamine salts of formula IV can be prepared, for example, by treating 2,2,- 3,3-tetramethylcyclopropane carboxylic acid in an inert organic solvent with a dilute aqueous alkali metal hydroxide solution or a triloweralkylamine. In carrying out this reaction, any conventional inert organic solvent can be utilized which is compatible with the amine or with the hydroxide solution, as the case may be. Among the preferred solvents are the lower alkanols, with ethanol being especially preferred. In carrying out this reaction, any alkali metal hydroxide or triloweralkylamine can be utilized. Among the preferred hydroxides and amines are the sodium and potassium hydroxides and triethylamine. In carrying out this reaction, temperature and pressure are not critical, and the reaction can be carried out at room temperature.

The silver salt of formula IV can be prepared by treating alkali metal salt of formula IV, such as the sodium salt, in an aqueous solution with silver nitrate. In carrying out this reaction, temperature and pressure are not critical, and the reaction can be carried out at room temperature.

The halide starting materials of formula V can be prepared, for example, by reacting a dihalobutyne of the formula:

wherein hal is as above, preferably chlorine; with an alkali metal salt of a phenol of formula VII. The reaction is suitably carried out in an inert organic solvent. Any conventional inert organic solvent can be used, with a lower alkanol being preferred, methanol and ethanol being especially preferred. In carrying out this reaction, temperature and pressure are not critical. Generally in carrying out this reaction, an elevated temperature is preferred, with a temperature of from 50C. to C. being especially preferred.

The halide starting materials of formula V can also be prepared, for example, by treating an alcohol starting material of formula III with a halogenating agent. Any conventional halogenating agent can be utilized in this reaction, with thionyl chloride or phosphorus tribromide in pyridine being preferred.

The reaction of an alkali metal salt, a silver salt or a triloweralkylamine salt of 2,2,3,3-tetramethylcyclopropane carboxylic acid, of formula IV, with a halide of formula V is suitably carried out in an inert organic solvent. In this reaction any conventional inert organic solvent can be utilized with a ketone, such as acetone or methyl ethyl ketone, or high-boiling ether, such as diglyme being preferred. In carrying out this reaction, temperature and pressure are not critical. Generally, it is preferred to carry out the reaction at an elevated temperature, the reflux temperature of the reaction mixture being especially preferred. It is also preferred to carry out this reaction under the atmosphere of an inert gas. In this reaction, the selection of the inert gas is not critical, nitrogen or argon being particularly preferred.

Still another method for preparing the compounds of formula I involves reacting a compound of formula VI with an alkali metal salt of a phenol of formula VII.

The starting materials of formula VI can be prepared, for example, by reacting an acid chloride or bromide of formula II with 4-chloro-2-butyn-l-ol. This reaction can be carried out under similar conditions to those described earlier in connection with the reaction of an acid chloride or bromide starting material of formula II with an alcohol starting material of formula III.

The alkali metal salts of the phenols of formula VII are known and can be prepared by conventional methods.

The reaction of a starting material of formula VI with an alkali metal salt of a phenol of formula VII can suitable be carried out in the presence of an inert organic solvent. In this reaction, any conventional inert organic solvent can be utilized, such as a hydrocarbon, a highboiling ether or a halogenated hydrocarbon. Benzene, toluene, and xylene, are the preferred hydrocarbons, diglyme is the preferred ether, and chloroform and methylene chloride are the preferred halogenated hydrocarbons. In carrying out this reaction, temperature and pressure are not critical. Generally, it is preferred to carry out the reaction at an elevated temperature, with the reflux temperature of the reaction mixture being especially preferred. Also, it i preferred to carry out the reaction under the atmosphere of an inert gas. In this reaction, any conventional inert gas may be utilized, with nitrogen or argon being particularly preferred.

The following examples illustrate the compounds of the invention. All temperatures are in degrees centigrade.

EXAMPLE I 7.4 g (0.457 mol) of 4-phenoxy-2-butyn-l-ol was dissolved in 65 ml of dry benzene and 7.5 ml of dry pyridine was added to the solution obtained. To this solution, there was added dropwise with stirring under a nitrogen atmosphere at 23C. over a period of 0.5 hours a solution of 7.3 g (0.0455 mol) of 2,2,3,3-tetramethylcyclopropane carboxylic acid chloride dissolved in 50 ml of dry benzene. The mixture was stirred at ambient temperature (25C.) for 16 hours. The precipitated pyridine hydrochloride was filtered off and washed with benzene. The combined benzene solutions were washed twice with -N hydrochloric acid, once with water, twice with 2-N sodium hydroxide solution, twice with 2-N hydrochloric acid, twice with saturated, aqueous sodium bicarbonate solution and twice with saturated, aqueous sodium chloride solution and then dried over anhydrous sodium sulphate. The sodium sulphate was filtered off, the filtrate was evaporated under reduced pressure, and the resulting syrup was distilled under high vacuum to yield 10.3 g of 4-phenoxy-2- butynyl-2,2,3,3-tetramethylcyclopropane carboxylate as a colorless liquid; boiling point (B.P.) 125 l27"C/l0- mml-lg;n j =1.5227.

EXAMPLE 2 10.5 g (0.5 34 mol) of 4-(4-chloro-phenoxy)-2-butynl-ol was dissolved in 70 ml of dry benzene, and 8.5 ml of dry pyridine were added to the solution. To this solution, there was then added dropwise with stirring under a nitrogen atmosphere over a period of 5 hours at C., a solution of crude 2,2,3,3-tetramethylcyclopropane carboxylic acid chloride, obtained by chlorinating 7.58 g (0.534 mol) of the corresponding carboxylic acid, in 60 ml of benzene. The mixture was then stirred at room temperature (C.) for 16 hours under a nitrogen atmosphere. The precipitated pyridine hydrochloride was filtered off and washed with benzene. The combined benzene solutions were washed twice with 5-N hydrochloric acid, once with water, three times with 2-N sodium hydroxide solution, once with 2-N hydrochloric acid, twice with saturated, aqueous sodium bicarbonate solution and twice with saturated, aqueous sodium chloride solution and then dried over anhydrous sodium sulphate. The sodium sulphate was filtered off and the filtrate was evaporated to a syrup under reduced pressure. The crude product was distilled twice to yield 8.3 g of 4-(4-chlorophenoxy)-2- butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate as a colorless liquid; B.P. l40C/ 10 mmHg; n 32 EXAMPLE 3 8.8 g of 4-(4-methyl-phenoxy)-2-butyn-l-ol was dissolved in 80 ml of dry benzene, and 8 ml of dry pyridine was added to the solution. The resulting solution as then treated dropwise with stirring with a solution of crude 2,2,3,3-tetramethyl-cyclopropane carboxylic acid chloride, obtained by chlorinating 7.1 g of the corresponding carboxylic acid with thionyl chloride, in 20 ml of benzene. The mixture was stirred at 20C. under a nitrogen atmosphere for 16 hours. The precipitated pyridine hydrochloride was filtered off and washed with benzene. The combined benzene solutions were washed twice with S-N hydrochloric acid, once with saturated aqueous sodium chloride solution, twice with 2-N sodium hydroxide solution, once with 2-N hydrochloric acid, twice with saturated aqueous sodium bicarbonate solution and twice with saturated aqueous sodium chloride solution then dried over anhydrous sodium sulphate. The sodium sulphate was filtered off, the filtrate was evaporated and the residue was distilled under high vacuum to yield 11.65 g of 4-(4- methylphenoxy)-2-butynyl-2,2,3,3-tetramethyl- 8 cyclopropane carboxylate; B.P. l 20"-l26"C/l0- mmHg; n 1.5213.

EXAMPLE 4 By utilizing the procedure of Example 3, 4-(3- methyl-phenoxy)-2-butyn-l-01 was treated with crude 2,2,3,3-tetramethyl-cyclopropane carboxylic acid to yield 4-(3-methyl-phenoxy)-2-butynyl2,2,3,3- tetramethyl-cyclopropane carboxylate; B.P. 145C/10 mmHg; n,, 1.5215.

EXAMPLE 5 9.82 g of 4-(3-chloro-phenoxy)2-butyn-l-ol was dissolved in ml of dry benzene, and 8 ml of dry pyridine was added to the solution. The resulting solution was then treated dropwise with stirring with a solution of crude 2,2,3,3-tetramethyl-carboxylic acid chloride, obtained by chlorinating 7.1 g of the corresponding carboxylic acid with thionyl chloride in 20 ml of benzene. The mixture was stirred at 20C. for 16 hours under a nitrogen atmosphere. The precipitated pyridine hydrochloride was filtered off and washed with benzene. The combined benzene solutions were washed twice with S-N hydrochloric acid, once with water, twice with 2-N sodium hydroxide solution, once with 2-N hydrochloric acid, twice with saturated aqueous sodium bicarbonate solution and twice with saturated aqueous sodium chloride solution and then dried over anhydrous sodium sulphate. The sodium sulphate was filtered off, the filtrate was evaporated and the residue was distilled under high vacuum to yield 12.35 g of 4-(3-chlorophenoxy)-2-butynyl-2,2,3,3 -tetramethyl-cyclopropane carboxylate as an oil; B. P. l24-l32C/l0 mmHg; "20

EXAMPLE 6 7.1 g of 2,2,3,3-tetramethyl-cyclopropane carboxylic acid was dissolved in ml of ethanol, and the solution was treated with 2-N sodium hydroxide solution until the mixture had a pH of 7. The mixture was evaporated under reduced pressure, and the residue was codistilled twice with ethanol and three times with benzene to constant weight. This yielded the sodium salt of 2,2,3,3-tetramethyl-cyclopropane carboxylic acid.

The foregoing sodium salt was suspended in 400 ml of dry diglyme and treated with 9.0 g of 1-chloro-4- phenoxy butync. The mixture was heated at C. with stirring for 6.5 days under a nitrogen atmosphere. The diglyme was removed under reduced pressure, and the residue was treated with a mixture of water and diethyl ether and then extracted with diethyl ether. The extracts were washed twice with 2-N sodium hydroxide solution, once with saturated aqueous sodium bicarbonate solution, twice with water and twice with saturated aqueous sodium chloride solution and then dried over anhydrous sodium sulphate solution. Removal of the sodium sulphate by filtration, evaporation of the fil' trate and distillation of the residue in high vacuum yielded 7.05 g of 4-phenoxy-2-butynyl-2,2,3,3- tetramethyl-cyclopropane carboxylate as an oil; B. P. l40-l50C/l0" mmHg; n 1.5227.

EXAMPLE 7 10.7 g of 2,2,3,3-tetramethyl-cyclopropane carboxylic acid in 25 ml of petroleum ether was treated at room temperature (25C.) with 7.5 ml of redistilled thionyl chloride and 2 drops of dimethylformamide. After 2,2,3 ,3-tetramethyl-cyclopropane "9 1.5 hours, all of thecarboxylic acid had dissolved. The solution wasthen evaporated, and the residue was codistilled with benzene to yield 2,2,3,3-tetra methylcyclopropane carboxylic acid chloride.

7.83 g of 4-chloro-2-butyn-l-ol in 100 ml of dry benzene and 12 ml of pyridine were treated under a nitrogen atmosphere with a solution of the acid chloride prepared as described in the preceding paragraph in 20 ml of benzene. The mixture was stirred for 1 hour at room temperature, and the precipitated pyridine hydrochloride was filtered off and washed with benzene. The combined benzene solutions were washed twice with S-N hydrochloric acid twice with 2-N sodium hydroxide solution, once with 2-N hydrochloric acid, twice with saturated aqueous sodium bicarbonate solution and twice with saturated'aqueous sodium chloride solution and then dried over anhydrous sodium sulphate. Removal of the sodium sulphate by filtration, evaporation of the filtrate and distillation of the residue under high vacuum yielded 10.0 g of 4-chloro-2- butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate;

'B. P. ll5-120C/0.7 mmHg; n 1.4900.

0.57 of sodium dissolved in 50 ml of dry ethanol was treated with a solution of 2.35 g of phenol in ml of dry ethanol, and the mixture was left to stand for 2 hours. Then, the ethanol was removed by evaporation and the residue was codistilled three times with benzene to yield a white powder, the sodium salt of phenol.

The foregoing sodium salt was suspended in 100 ml of dry diglyme, and 5.71 g of 4-chloro-2-butynylcarboxylate was added thereto. The mixture was heated at 120C. for 48 hours under a nitrogen atmosphere. The precipitated sodium chloride was then filtered off. The solution was then evaporated under a water-pump vacuum and water was added to the residue. The mixture was then extracted three times with diethyl ether, and the com bined diethyl ether extracts were washed once with 2-N sodium hydroxide solution and twice with saturated aqueous sodium chloride solution and dried over anhydrous sodium sulphate. Removal of the sodium sulphate by filtration, evaporation of the filtrate and distillation of the residue under high vacuum yielded 3.95 g of The following Examples illustrate insecticidal compositions containing the esters of the invention.

EXAMPLE 8 2.5 g of 4-phenoxy-2-butynyl-2,2,3,3-tetramethylcyclopropane carboxylate was dissolved in sufficient kerosene to give a final volume of 100 ml. The resulting solution was suitable for use as a spray.

EXAMPLE 9 percent of active ingredient.

EXAMPLE I0 I Twenty g of 4-pherioxy-2-butynyl-2,2,3,3-tetrameth- 4-phenoxy-2-butynyl-2,2,3,3-tetramethylcyclopropane carboxylate; B. P. 1 l45C/1( yl-cyclopropane carboxylate, 10 g of nonoxylon-lS (a non-ionic surfactant) and g of xylene were thoroughly mixed to give a solution which can be used as an emulsifiable concentrate. Before use, the emulsifiable concentrate was emulsified in sufficient water to give a ten-fold dilution.

We claim: 1. A compound of the formula:

wherein X is hydrogen, lower alkyl, or chlorine. 2. The compound of claim 1 wherein said compound has the formula:

3. The compound of claim 2 wherein said compound is 4-(4-chloro-phenoxy)-2-butynyl-2,2,3,B-tetramethyl-cyclopropane carboxylate.

4. The compound of claim 1 wherein said compound has the formula:

wherein Y is hydrogen or lower alkyl substituted in the ortho or para positions.

5. The compound of claim 4 wherein Y is hydrogen.

6. The compound of claim 5 wherein said compound is 4-phenoxy-2-butynyl-2,2,3,B-tetramethylcyclopropane carboxylate.

7. The compound of claim 4 wherein Y is lower alkyl in the ortho position.

' 8. The compound of claim 7 wherein said compound is 4-(Z-methyl-phenoxy)-2-butynyl-2,2,3,3-tetramethyl-cyclopropane carboxylate.

9. The compound of claim 4 wherein Y is lower alkyl in the para position.

10. The compound of claim 9 wherein said compound is 4-(4-methyl-phenoxy)-2-butynyl-2,2,3,3- tetramethyl cyclopropane carboxylate.

* k t a 

